There's been a bit of a stir this week concerning a new U.S. Customs facility at Abu Dhabi International Airport, which is now offering preclearance for all U.S. citizens heading directly to the United States from Abu Dhabi. That means that U.S. citizens can pass through American customs before they arrive on American soil. Though the UAE boasts one of the world's most progressive economies, the new service has raised eyebrows among American pilots and certain members of Congress who believe that the new facility gives an unfair competitive advantage to Etihad Airways, which operates the only route between Abu Dhabi and the U.S.. Politics aside, preclearance is popular among American travelers, and for good reason. It helps them skip lengthy customs lines at home. And though it’s still only available at a few airports worldwide, here are the nuts and bolts of the program and how it can help you when you're flying back home.

What is Preclearance? The CBP Preclearance program essentially inserts a cadre of U.S. Customs and Border Protection agents inside an international airport. Once a U.S. citizen passes through that country’s own security lines, they are then allowed to pass through an additional security line — one manned by American agents. This procedure mimics the procedure used in U.S. airports, and allows the passenger to clear both security and customs before ever landing on U.S. soil. It requires an extra 10 to 20 minutes prior to take-off, but it allows flyers to skip massive immigration lines once they return home.

How does it help? Preclearance allows U.S. citizens to handle the immigration process at their origin. Once you land in the U.S., it’s as if you've arrived from a domestic origin. While this is great, it does require more time. You'll need to arrive a solid half-hour earlier than you otherwise would, and you'll need to be mentally prepared to take your shoes and belt off twice in a row, and in a relatively short amount of time. Just remember to pack and dress as if you were expecting a typical U.S. security shakedown, including America's carry-on liquid rules.

Where is it offered? As of today, Customs and Border Patrol Preclearance is available in 16 international airports: Calgary; Edmonton; Halifax; Montreal; Ottawa; Toronto; Vancouver; Victoria; Winnipeg; Freeport (Bahamas); Nassau (Bahamas); Bermuda; Aruba; Shannon (Ireland); and Dublin (Ireland). Oh, and Abu Dhabi, of course. Beyond that, the program has been slow to expand. The addition of Abu Dhabi to the roster was the first since the 1980s.

What’s the fuss? As it turns out, the government of the UAE is absorbing 85 percent of the costs incurred in adding the preclearence facility. That includes the salaries of U.S. Customs and Border officials who will have to live and work in Abu Dhabi in order to implement U.S. security measures. Critics argue that the UAE’s offer to pay such a significant portion of the costs will sway flyers to Etihad and to Abu Dhabi, but for passengers who simply want a more convenient arrival, they’ll likely appreciate the new fascility. At the very least, this could have frequent travelers to the Middle East considering non-stop flights to Abu Dhabi over the far more transited Dubai.